#include <iostream>
using namespace std;

void func (int a, int b = 20, int c = 30);
//error
//void func1 (int a = 0, int b = 20, int c){}
//void func (int a) {} //注意不要因为重载而出现歧义错误

int main (void)
{	
	func (100, 200, 300);// 100 200 300
	func (100, 200); //100 200 30
	func (100); //100 20 30
	return 0;
}

void func (int a, int b, int c) {
	cout << "a=" << a << endl;
	cout << "b=" << b << endl;
	cout << "c=" << c << endl;
}
